Motor-control system



Q a March 1927' E. STAPLES 619 380 MOTOR CONTROL SYSTEM 1 Z! 1 :62 2. Sequence of Swi/ches 5 Km. ,aer'br:

Rack Enyayed I I g 22 INVE rfOR f WITNESSES.

, /j f/oen A 5707 0/65 March 1, 1927.

1,619,380 E. l. STAPLES v MOTOR CONTROL SYSTEM Filed Nov. 8, 1924 2 Sheets-Sheet 2 770//e z/ I 6 37 38 I? v 16 /Z 3 \32 ll 2' Z7 .,Z6 ,29 ,30

- INVENTOR WITNESSES. [570/677 Jfg o/ES Patented M... 1, 1927.

UNITED STA TES PATENT OFFICE.

ELDEN I. STAPLES, OF EAST PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTING- 'HOUSE ELECTRIC 8t MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- yum.

MOTOR-CGNTROL SYSTEM.

Application filed November 8, 1924. Serial No. 748,560.

My invention relates to motor control system and it has particular relation to control systems employed to govern the operation of a plurality of motors for actuating a railway motor vehicle in mountainous country. 7 One object of my invention is to provide a system of control for governing a plurality Y of motors that actuate a motor vehicle or comotive over railroad track in mountainous country. in which the grade of the track 1s so heavy that rack sections must be provided between the rails of the track to engage one or more gear members mounted upon the vehicle.

A second object of my invention isto pro vide 'acontrol system for governing the operation of a plurality of motors whereby the ratio of speed between certain motors may be fixed at a predetermined value.

. Another object of my invention is to provide a control system for so governing both a group of motors that are employed to drive the wheels of a railway motor vehicle and another group of motors that are employed to drive a gear wheel which engages a rack member that the peripheral speed of the gear wheel and the wheels of the vehicle are substantially equal at the time said gear wheel engages. the rack member.

Another object of my invention is to provide means for simultaneously governing the speed of the wheels of a motor vehicle and a gear member mounted thereon and adapted to. engage a rack member longitudinally mounted between the rails upon which the vehicle operates.

Still another object of my invention is to provide a system of control for a railway motor vehicle whereby a. locomotive may be driven upon a portion of the track in which a rack section is located without danger of stripping the teeth of either the rack section or the gearwheel which is mounted upon the locomotive and adapted to engage the rack section.

Briefiy speaking, my invention comprises providing a control system for governing a tion. The motors employed for abnormal operation actuate a gear wheel which is adapted to engage a rack member which is securely mounted between the rails over which the vehicle travels. The control system so governs the speed of all the motors that the tors may ratio of speed of the different mobe so fixed that the peripheral speed of the adhesion wheels and the gear wheel may be made substantially equal at the time the gear For a wheel engages the rack member. better understandmg of my invention, reference may be made to the accompanying drawing Figure 1 of which is a diagrammatic view of a motor control system constructed in accordance with my invention and employed to govern a plurality of motors of a railway motor vehicle which operates Fig. 2

through mountainous country. is a sequence chart showing the sequence of operation of the switches illustrated by Fig. 1 of the drawing.

Figs. 3 to 8, inclusive, are diagrammatic views showing the main control circuits that are illustrated by Fig. 1 of the drawing at different periods during the placing in operation of the motors for abnormal operation during the period said vehicle is passing over 1s very g Fig. 9

a portion of track where the grade reat. shows a cross-sectional view of railroad track upon which is mounted a railway motor vehicle constructed in accordance with my invention, only the lower portion of the vehicle being illustrated.

Fig. 10 is a longitudinal sectional view of the rack drawing member illustrated in Fig. 9 of the and the gear wheel of the locomotive which engages the rack member.

Fig. 11 is a view, in side elevation, of a wheel of a vehicle and a motor mechanically connected thereto.

Referring particularly to Fig. 1 of the drawing, a plurality of switches 1 to 17 inclusive, and a plurality of accelerating resistors 18 and 19 are employed to govern the operation of a plurality of dynamo-electric machines or motors 21 to 26, inclusive, in a hereinafter more fully described.

The motors 21 to 24 inclusive, are employed to drive stitute a a motor vehicle, of which they conpart, during normal operation of the vehicle and the motors 25 and 26 are employed f vehicle.

or abnormal operation of the same The motors 21 to 26, inclusive, may

be energized in a manner hereinafter more fully described from a source of electrical energy marked Trolley. The motors 21 to 26, inclusive, are provided with corre sponding series fieldnnagnet windings 27 to 32, inclusive, and with corresponding armatures 33 to 38, inclusive. All of the motors 21 to 26, inclusive are designed to be of the same size, shape and to develop the same horse power under like electrical conditions.

The armatures 33 to 36, inclusive, of the motors 21 to 24, inclusive, are mechanically connected to a plurality of wheels 41 by means of axles 42, in the manner illustrated by Fig. 11 of the drawing. The wheels 41 are adapted to roll upon the rails 43 which are securely mounted upon the ties 44 constituting part of the track 45 (see Fig. 9). The wheels 41 have smooth flanges and the tractive effort that may be applied through the wheels 41 is limited by their adhesion to the rails 43.

The tractive force which the motors 21 to 24, inclusive, transmit to the vehicle is limited by the adhesion of the wheels 41 to which they are mechanically connected. The armatures 37 and 38 of the motors 25 and 26, respectively, are mechanically connected to a gear wheel 46 in a manner hereinafter more fully described. The gear wheel 46. which is securely mounted upon an axle 47 of the vehicle, is adapted to engage a rack member 48 which is securely mounted be tween the rails 43 forming a part of the track 45.

The motors 25 and 26 are each connected to corresponding gear members 49 by means of rotatable shafts 50. The gear members 50 are adapted to engage the gear member 51 which is securely mounted upon the rotatable shaft 47. Both the gear wheel 46 and rack member 48 are provided with a plurality of corresponding teeth 52.

The design of the gear wheels 46, 49 and 51 is such that the motors 25 and 26 must travel at approximately twice the speed of the motors 21 to 24, inclusive, for the peripheral speed of the gear wheel 46 to be the same as that of the peripheral speed of the vehicle wheels 41.

Referring again particularly to Fig. 1 of the drawing, switches 1 to 5, inclusive, are employed to shunt portions of the resistor 19 and switches 6 to 10, inclusive, are employed to shunt portions of the resistor 18. Switches 12 and 13 are employed to connect the series field-magnet windings 31 and 32 of the motors 25 and 26, respectively, in series relation with the series field-magnet windings 27 to 30 inclusive, and armatures 33 to 36 inclusive of the corresponding motors 21 to 24, inclusive. The parallel-connecting switch 14 is employed to connect the series field-magnet windings 27 to 30, inclusive, in series relation with the armatures 33 to 36 inclusive, of the motors 21 to 24 inclusive. The ground switch 15 is employed to connect the series field magnet windings 31 and 32 of the motors 25 and 26 respectively, directly to ground. The line switches 16 and 17 are employed for connecting the group of motors 21 to 24, inclusive, and the group of meters 25 to 26, respectively, to the source of electrical energy marked Trolley.

The description of the operation of my control system will be confined to the operation of the vehicle just prior to and just after the engagement of the rack wheel 46 with the rack member 48, for this invention is intended to eliminate the ditficulties encountered at the time the rack wheel 46 is brought into engagement with the rack member 48.

These ditliculties are caused by the shock of engagement of the teeth 52 of the gear wheel 46 meshing with teeth 52 of the rack member 48. This impact is very great because of the relatively great rotary speed of the rack motor armatures 37 and 38, and their considerable mass.

Let us suppose that a railway vehicle constructed in accordance with my invention is approaching a portion of the track that is provided with a rack member 48, when it will then be the duty of the engineer to slow down the speed of the vehicle. The decrease in the speed of the locomotive is eifected by first connecting the motors 21 to 24, inclusive, in the manner illustrated by Fig. 3 of the drawing. At this time, the motors 25 and 26 are inoperative. The accelerating switches 1 to 5 inclusive are closed and a circuit is established from the source of electrical energy marked Trolley through the line switch 16. accelerating switches 1 to 5. inclusive, armatures 33 to 36, inclusive, of the corresponding motors 21 to 24 inclusive, parallel-connecting switch 14 and series field-magnet windings 27 to 30, inclusive, of the co responding motors 21 to 24, inclusive, to ground. The speed of the motors 21 to 24, inclusive, is then decreased by consecutively opening the switches 5, 4, and 3 in the order illustrated by steps 2 to 4. inclusive, of the sequence chart of Fig. 2, the circuit corresponding to position 4 of the sequence chart being illustrated in Fig. 4. When the switches 3 to 5, inclusive, have been opened the speed of the motor vehicle will become practically 5 kilometers per hour. It is desirable that the speed of the motor vehicle remain at this rate until after the rack wheel engages the rack member 48.

The next step in the operation of my control system is to so energize the field magnet winding 31 and of the motors 25 and 26, respectively, that their 'energization shall be the same as the series field-magnet windings 27 to 30, inclusive, of the corresponding motors 21 to 24, inclusive. This is efi'ected by closing the series-connecting switches 12 and 13 as illustrated by step of the sequence chart of Fig. 2 and by Fig.

5" of. the drawing.

The parallel-connecting switch 14 is then opened, 1n accordance with position 6 of the sequence chart of Fig. 2,':thereby energizing the series field-magnet winding 31 and 32 III the motors 21 to 24, inclusive.

of the motors '25 and 26 which have been previously connected in series relation with The circuit corresponding to position 6 of the sequence chart is illustrated by Fig. 6 of the drawing.

7. The accelerating switches 1' and 2, the

line switch 16, the series connecting switches 1 12 and 13 are closed, to correspond to position '6 of the sequence chart of Fig. 2, therer 24, inclusive,

. series field-magnet windings 31 and 32 of the motorsf25 and 26, respectively, and series field-magnet windings 27 to 30, inclusive, of the corresponding motors 21 to 24, inclusive, to ground.

The next step in effecting the operation ofthe motor-s25 and 26 is to close the parallel-connecting switch 11, thereby connecting the armatures 37 and 38 of the motors 25 and 26, respectively, in parallel relation parallel circuits which have with the armatures 33 to 36, inclusive, of the corresponding motors 21 to 24, inclusive. A portion of the accelerating resistor 18 is connected in series relation with the arma tures 37 and 38 of the motors 25 and 26, respectively, to prevent a heavy surge of electrical energy through the armatures 37 and 38 prior to their rotation. .Fig. 7 ot' the drawing which corresponds to position 7 of the sequence chart of Fig. 2, illustrates the just been described.

Thenext step in the acceleration of the motors 25 and 26 is to close the switches 9 and 10, in the order illustrated by positions 8 and 9 of the sequence chart of Fig. 2

thereby shunting all of the accelerating re sistor 18 that is vconnected in series relation with the motors 25 and ,26.

Upon the closure of the switches 9 and 10, the voltage across the terminals of the armatures 37 and 38 of the motors 25 and 26, respectively, is double that of the armatures 33 to 36, inclusive, of the corresponding motors 21 to 24, because there are two armatures connected in series relation in one circuit and four armat-ures are connected in series relation-1n the other circuit and the V voltage of each circuit is the same.

With the energization the same in all of the field magnet windings 27 to 32, inclusive, off-the corresponding motors 21 to 26, inclusive, and with the voltage across the terminals of each of the armatures 37 and 38 ot' the motors 25 and 26, respectively, double that of the voltage across the terminals of each of the armatures 33 to 36, inclusive, of the corresponding motors 21 to 24, inclusive, the speed of the motors 25 and 26 will be approximately double that of the motors 21 to 24, inclusive.

Vith the speed of the armatures 37 and 38 of the motors 25 and 26, respectively, double that of the armatures 33 to 36, inclusive, of the corresponding motors 21 to 24, inclusive, the peripheral speed of the gear wheel 46 will be substantially the same as the peripheral speed of the flanges of the wheel 41 because the gear reduction between the motors 25 and 26 and the gear wheel 46 is approximately double that of the reduction between the motors 21 to 24, inclusive, and the vehicle wheels 46. By having the speed of the motors 25 and 26 double that of the motors 21 to 24, inclusive, it is possible for the motors 25 and 26 to supply as much mechanical energy in the driving of the vehicle as the motors 21 to 24, inclusive, supply. In other words, the tractive effort is distributed equally between the wheels 41 and the gear wheel 46 of the locomotive.

At this stage in the operation of the motors 21 to 26, inclusive, the operator permits the locomotive vehicle to travel forward until the gear wheel 46 engages the rack member 48. As the peripheral speed of the gear wheel 46 is substantially the same as the peripheral speed of the flanges of the wheels 41, there is no excessive horizontal thrust upon the teeth of the rack member 48. When the rack wheel 46 has engaged the rack member 48, the necessity for maintaining the peripheral speed of the gear wheel 46 and the wheels 41 precisely the same is eliminated, as they are no longer subject to the shock of engagement.

The next step in the acceleration of the motors is to close switches 14, 15,- and line switch 17, and open switches 11, 12, and 13, in accordance with position 10 of the sequence chart of Fig. 2. The motors 25 and 26 are now connected in parallel relation to the motors 21 to 24, inclusive, between the source of electrical energy marked Trolley and Ground. That portion of the resistor 18' that remains in series relation with themotors 25 and 26 is substantially equal in electrical resistance value to that portion of the resistor 19 that remains in series relation with the motors 21 to 24, inclusive. The group of motors 21 to 24, inclusive, and the group of motors 25 and 26 are accelerated uniformly by simultaneously closing switches 8 and 3 in accordance with step 11 of the sequence chart of Figure 2, thereby shunting substantially equal portions of the resistors 18 and 19 respectively. The switchesa and 7 are next closed simultaneously to shunt equal portions of the resistors 18 and 19, this corresponds with step 12 of the sequence chart of Fig. 2 of the drawings.

Lastly, the switches 5 and (3 are closed simultaneuosly in accordance with step 13 of the sequence chart of Fig. 2, thereby completely shunting all of the resistors 18 and 19 and establishing the circuits illustrated by Figure 8 of the drawing. The one circuit, which is established, extends from the source of electrical energy marked Trolley through line switch 17, accelerating switches 6.1:0 10, inclusive, arn'iatures 37 and 38 and series field-magnet windings 31 and 32 of the motors and 26, respectively, and ground switch 15 to ground. The other circuit extends from a source of electrical energy marked Trolley through the line switch 16, accelerating switches 1 to 5, inclusive, armatures 33 to 86, inclusive, of the corresponding motors 21 to 24, inclusive, switch 14, and series field magnet windings 27 to 30, inclusive. of the motors 21 to 24, inclusive, to ground.

From the above description, it is apparent that I have provided means whereby it is possible to bring a motor vehicle upon a portion of railway track in which a rack member is securely fastened, to engage a gear wheel which is mounted upon the locomotive, without injuring the gear wheel or the rack member by the shock of their engagement. I have also provided means for so controlling the energization of the windings and armatures of. a plurality of motors employed to drive the motor vehicle that more power is supplied by certain of the motors than by others, and the speed of the motors is maintained at a predetermined ratio to effect desirable operation of the locomotive when operating upon tracks of extremely heavy grade.

Vhile I have illustrated my invention in its preferred form, it is apparent that minor modifications may be made in the arrange-- ments of circuits and apparatus employed without departing from the spirit of my in vention. I desire, therefore, to be limited only by a scope of appended. claims.

I claim:

1. In a motor control system, the combination with a. plurality of dynamo-electric machines, of a mechanical load driven by said machines, means for mechanically connecting said machines to said load whereby certain of said machines perform more work than others, and means for energizing each of said machines proportionally to its predetermined share of said mechanical load.

2. In a motor vehicle, the combination with a vehicle having a plurality of wheels, of a motor for driving said wheels, means for mechanically connecting said wheels to said motor, an additional wheel mounted on said vehicle, a second motor, and means for mechanically connecting said additional wheel to said motor, said second mechanical means differing from said first mechanical means whereby said motors must travel at different speeds to maintain the peripheral speed of said wheels equal, and means for energizing said motors to maintain equal peripheral speed for all of said wheels.

In a motor vehicle, the combination with a vehicle having a plurality of wheels, of a motor for driving said wheels, means for mechanically connecting said motor to said wheels, a gear wheel mounted upon said vehicle for actuating said vehicle on heavy grades,a second motor for driving said gear wheel during abnormal operations, meansfor mechanically connecting said second motor to said gear wheel and means for energizing said motors to maintain the peripheral speed of said wheels and said gear wheel equal until said gear wheel actuates said vehicle.

In a motor control system, the combination with a vehicle having a plurality of wheels, of a motor for driving said wheels, means for mechanically connecting said motor to said wheels, a gear wheel mounted upon said vehicle, a second motor tor driving said gear wheel during abnormal operations, means comprising a gear member for mechanically connecting said second motor to said gear wheel, said mechanical means being so constructed that the speed of said first and second motor must differ for the peripheral speed of said gear wheel to equal the peripheral speed of said wheels and means for energizing said motors to maintain the. peripheral speed of said wheels and said gear,.wheel substantially equal during a predetermined time.

5. In a control system, the combination with a. plurality of dynamo-electric ma-.

chines, each of said machine having an armature and a field-magnet winding, of means for connecting said windings of said machines in series relation one with the other, means for connecting in unequal groups certain of said armatures of said machines in series relation one with the other, and means for connecting said unequal groups of armatures in parallel relation one to the other.

6. In a control system, the combination with a plurality of dynamo-electric machines, each of said machines having an arlnature and a fieldanagnet winding, of means for connecting said windings of said machines in series relation one with the other, means for connecting in unequal groups certain of said armatures of said machines in series relation one with the other, one of said groups having double the number of armatures of the other group,

in parallel relation with said first group of armatures and means for making the voltage across one group of armatures the same 1 as across another group of armatures.

, 8. In a control system, the combination with a plurality of motors, each of said motors having an armature and a field magnet winding, of a resistor, a switch for connecting the armatures and field-magnet windings of four of said motors in series relation one with another and with said resistor, two

switches for connecting the field-magnet windings of two of said motors in series relation with said four motors and said resistor, a parallel-connecting switch and a second resistor for connecting the armatures of said two motors in parallel relation to said armatures of said four motors, a source of electrical energy, a line switch for connecting said four motors to said source of energy and a second line switch for connecting said second resistor directly to said source of electrical energy and independent of said parallel-connecting switch.

9. The method of energizing a plurality of motors, each having an armature and a field-magnet winding that comprises connecting certain of said motors in series relation one with another, then inserting the field-magnet windings of other of said 1110- tors in series relation with said series connected motors and then connecting the arinatures of said other motors in series relation one with another and in parallel relation with armatures of said series connected motors.

10. The method of energizing a plurality of motors, each having an armature and a field-magnet winding whereby a group of said motors are energized to rotate their respective armatures at a predetermined speed, the remaining motors next having their field-magnet windings energized to the same value as the field magnet windings of said group of motors, and then energizing the armatures of said remaining motors to double the value of the energization of each armature of said first group.

In testimony whereof, I have hereunto subscribed my name this 7th day of October,

ELDEN I. STAPLES. 

